Prolonging the shelf life of fresh root vegetables

Abstract

The shelf life of root crops such as raw carrots can be substantially increased by subjecting the raw carrots, in one embodiment, to a process including (a) a mild heat treatment effective to reduce the microflora of the carrots but not to adversely affect the organoleptic qualities of the raw carrots, (b) the rapid cooling of the heat treated vegetable and (c) placing the vegetable in a sealed container to prevent microbial recontamination and maintain the vegetable in a viable condition. In another embodiment, the process includes subjecting the carrots to a vacuum, breaking the vacuum in the presence of water and placing the vegetable in a sealed container to prevent microbial recontamination and maintain the vegetable in a viable condition.

What is claimed is: 
     
       1. A process of maintaining a fresh root vegetable in a viable form which comprises: (a) peeling the surface of a fresh root vegetable,   (b) providing the vegetable in uniform sized pieces,   (c) subjecting the vegetable to a vacuum of less than about 20 inches Hg absolute for about 2 to about 10 minutes,   (d) breaking the vacuum in the presence of chlorinated water,   (e) removing surface water from the vegetable, and   (f) providing the vegetable in a sealed container effective to prevent microbial recontamination of the vegetable and having a gas permeability and a ratio of the mass of vegetable to the container surface effective to maintain the vegetable in a viable condition.   
     
     
       2. A process of maintaining a fresh root vegetable in viable form which comprises: (a) peeling the surface of a fresh root vegetable,   (b) providing the vegetable in uniform sized pieces,   (c) contacting the vegetable with chlorinated cold water under atmospheric conditions for up to about five minutes,   (d) removing surface water from the vegetable, and   (e) providing the vegetable in a sealed container effective to prevent microbial recontamination of the vegetable and having a gas permeability and a ratio of the mass of vegetable to the container surface effective to maintain the vegetable in a viable condition, with the proviso that said vegetable is not subjected to heat treatment during said process.   
     
     
       3. A process according to claims 1 or 2 including the following steps conducted prior to step (a) of claim 1 or step (a) of claim 2, respectively: removing the green leafy top of the fresh root vegetable, and   effectively washing the exterior surface of the vegetable to remove soil.   
     
     
       4. A process according to claim 1 wherein in step (c), the vacuum is about 1 to about 20 inches Hg absolute and chlorinated water is present while the vegetable is subjected to vacuum. 
     
     
       5. A process according to claims 1 or 2 wherein the sealed container of step (f) of claim 1 or step (e) of claim 2, respectively, has the following properties: a gas permeability of about 50 to about 300 cc of O 2  /100 in 2  -atm.-24 hrs., about 200 to about 800 cc of CO 2  /100 in 2  -atm.-24 hrs. and a moisture transmission rate of less than about 1.5 g/100 in 2  -24 hrs. -90% R.H., 70° F. and a ratio of the mass of the vegetable to the container surface of about 1 to about 6 g/in 2 .   
     
     
       6. A process according to claims 1 or 2 wherein the sealed container of step (f) of claim 1 or step (e) of claim 2, respectively, comprises foamed polypropylene. 
     
     
       7. A process according to claims 1 or 2 wherein the vegetable is carrots, turnips, rutabaga or radishes. 
     
     
       8. A process according to claim 7 wherein the vegetable is carrots. 
     
     
       9. The product prepared by the process of claims 1, 2 or 4. 
     
     
       10. The product prepared by the process of claim 3. 
     
     
       11. The product prepared by the process of claim 5. 
     
     
       12. The product prepared by the process of claim 6. 
     
     
       13. The product prepared by the process of claim 7. 
     
     
       14. The product prepared by the process of claim 8.